Explaining The Photography Triangle

I thought I would write a post explaining the photography triangle. This triangle is ISO, Shutter Speed, and Aperture. And they are the three major camera settings you need to adjust to attain the best picture. When you first got your DSLR you probably spent some time shooting on the Green Square or P mode. (Maybe you have never left!) The Green Square puts your camera in fully automatic mode. It’s so automatic that you can’t make any settings changes. P mode therefore is the same as the Green Square but you get to override any setting you want.

Aperture Priority mode (AV) and Shutter Priority Mode (TV) are very similar to P mode. In AV mode you set the Aperture (f-stop) or how much light your lens lets in, and the camera sets the Shutter Speed and ISO for you. And in TV mode, you set the shutter speed and the camera sets the Aperture and ISO.

But sometimes (usually when outdoors) you might have it on P, TV or AV and you still can’t get a good shot. What can you do? This is the time to try Manual (M) mode. I know, fully manual mode scares you more than getting a haircut from Freddy Krueger. It’ll be ok! Your camera isn’t going to explode.

I google searched for a chart on the photography triangle and I saw this somewhat confusing thing:

If I showed this to my wife, she’d be more confused. So I made this one, your camera’s #s may vary:

In brief: As you raise ISO you brighten the image, but add more noise. As you lower Aperture/F-stop you create more shallow depth of field (smaller focus area). And finally increasing Shutter Speed will freeze fast action and increasing it will create motion blur. And that’s why you can’t take an in-focus picture in auto mode sometimes. The camera has automatically set the shutter speed too slow. Plus your shooting handheld and moving slightly. You need a faster shutter.

So put your camera on M. Aim your camera at your subject and give the shutter button a half press. Now look at the top screen on your camera. Or if it doesn’t have one, hit the Q button (for Canon Cameras) to see the below screen.

Now decide how in-focus you want your pic to be. Set the Aperature/F-stop to its lowest number for narrowest area in focus, and highest number for everything in focus.

Next set your ISO depending on how bright it is. In bright sunlight start with 100 ISO. In a dark room, pump it up more. Just remember the higher ISO goes the more noise or grain your image will have. So don’t go too nuts with ISO.

Ok, whew, 2 of our 3 settings are locked in. Now take a look at your cameras light meter. It looks like this:

Select the Shutter Speed and begin changing it until you see that little needle on the light meter hit the center of the meter. That’s your camera telling you that you’ve got a good shot going. Take a picture! How does it look on your screen? DON’T TRUST YOUR SCREEN! That little screen can lie, especially when you’re outside in bright daylight. For a better computerized look analysis of your exposure, hit the info button a couple times while viewing your pic, you’ll get to your histogram:

That there is one sexy looking histogram. See how the data is almost touching the right side of the chart? That means you’re just slightly under exposed. A little underexposed is ok. You can brighten things up later. If your histogram is jammed to the right and up against the right of the chart, you’re overexposed, and it’s much harder to pull back from overexposure. This is why shooting in RAW is a good thing. RAW collects more data than JPEG and you can rescue images over/under exposed in RAW better than if they were shot in JPEG.

Whew, I know that was a lot to take in. But practice! It’s only digital photography, you aren’t ruining film that you have to pay for. Play. Practice. Delete the uglies. Have fun!